For each of these factions – Clinton, Sanders, Trump, Cruz, and Rubio – the other four alternatives offer almost nothing. This is a formula for widespread dissatisfaction on election night — and a new president with almost no mandate on January 20, 2017.

Will the Democratic and Republican parties break up? The enormous logistical challenges of building a new nationwide party from scratch make it unlikely that any faction will want to completely break away. But with such intense and irreconcilable divisions about the role of government, policy priorities, and just what the country needs, the two parties are already broken. And neither one looks likely to be genuinely united any time soon.